Cylinder lock



N. B. HURD CYLINDER LOCK Jan. 4, 1938.

Filed May 6, 1957 INVENTOR NORMA/V 5. Hl/RD ATTORNEYS Patented Jan. 4, 1938 UNITED STATES PATENT OFFICE CYLINDER LOCK Application May 6, 1937, Serial No. 141,045

Claims.

This invention relates to improvements in cylinder locks and. is primarily an improvement on the construction set forth in my former patent, No. 1,922,438, granted August 15, 1933.

My invention is particularly useful when employed with corridor locks having a fixed outer knob or one that may be dogged so that admission may be had only by the use of an appropriate key or keys. Briefly stated, my purpose is to construct a cylinder lock in which one key is provided that is capable of operating the latch-bolt only, while a different key is provided that is capable of operating both the dead-bolt and the latch-bolt.

My main object is to accomplish the above end by a simple, durable and dependable construction, which I shall now set forth. In the accompanying drawing- Fig. l is a side elevation of the conventional door lock of the mortise type, the upper part of the cap being removed to show a portion of the interior mechanism, and also showing the position that the cylinder lock occupies relatively thereto;

Fig. 2 is a relatively enlarged side elevation of the cylinder lock detached;

Fig. 3 is a cross-sectional View of Fig. 2 showing one position of the parts when one key is being used;

Fig. 4 is a similar View showing the position of said parts when a different key is used;

Fig. 5 is a side elevation showing the position of two difierent keys with relation to one of the elements that I will later term a plug blocking device or tumbler.

I represents a lock case, 2 the face-plate, 3 the spring latch-bolt, 4 the dead-bolt, and 5 the dead-bolt tumbler. 6 is a stud on the dead-bolt tail upon which is mounted a latch retracting lever or member I. 8 is a link pivoted at its upper end at 9, its lower end being slotted to stand over the stud 6. I ll is a lever pivoted at stud H on the side of the dead-bolt tail and engaging one arm of the latch-bolt retracting lever to move the same and retract the latchbolt. Part of the lever I0 is designed to be engaged by a key controlled roll-back I 2 on the cylinder lock when the dead-bolt is retracted as shown in Fig. 1. By depressing this end of lever It, the latch-bolt 3 is retracted. When the dead-bolt is advanced, the lever I0 is similarly advanced to a position out of range of the roll-back I2 and hence cannot be operated thereby until the bolt has been again retracted. 55 Thus far I have described a well known form of corridor mortise look as typical of a lock with which my improved cylinder lock may be used to advantage.

, Now, turning to the cylinder lock construction, I4 is the cylinder lock body, or cylinder, as it is sometimes termed. I5 is a rotatable key plug on the rear end of which is mounted the rollback I2 or equivalent device. lB-Hi represent the usual locking tumbler sections in the plug and cylinder respectively. I! is a plug blocking device or tumbler of substantial length, backed by a spring I1 and capable of reciprocal movement only in a passage in the cylinder body. This blocking tumbler is in approximately the same cross-sectional plane with the rearmost locking tumbler I6 in the cylinder but is positioned at a different angle to the axis of the plug from that of said locking tumbler. A similar blocking tumbler H" is similarly located in the cylinder body on the opposite side of the locking tumbler I6. tumbler is beveled off on the side toward the locking tumbler I6. Means are provided to prevent either of said locking tumblers from rotating on their axes to thereby guarantee that the beveled ends will always face properly. In this case both blocking tumblers and the passages in which they stand are of angular cross-section and hence the tumblers cannot turn. The plug l5 has the usual slotted keyway which cuts through the side 0 of the plug opposite the locking tumblers l6. When a key is inserted, the ends of the tumblers l6 stand flush with the outer cylindrical surface of the plug and the back of the key bridges that much of the keyway slot occupied thereby so as to be flush with said cylindrical surface. 3 is a short key, the back of which stops short of the blocking tumbler l1, and consequently when the plug is turned counterclockwise to the position shown in Fig. 3, the blocking tumbler i! will be projected into the key slot and will check further rotation in that direction. If, however, the plug l5 should be turned in a clockwise direction as soon as the key slot reaches the blocking tumbler I7" further turning in that direction is stopped.

If a long key 59 is used, the back of said key will extend sufiiciently far into the slot to bridge the same underneath the blocking tumblers Il-l'l" and hence with such a key, the plug l5 may be turned freely in either direction to an unlimited extent.

Operation-To illustrate how my improved cylinder lock functions, I have shown it as associated with a well known type of mortise lock The end of each blocking having a latch-bolt and a dead-bolt. Assuming the parts stand as indicated in Fig. l with the dead-bolt retracted. If the roll-back i2 is operated by a short key it may be turned in a counterclockwise direction approximately to the position shown in Fig. 3, which is insuflicient to depress the tumbler 5 and permit the dead-bolt to be projected. If the roll-back I2 is turned in a clockwise direction, it may move far enough to engage the lever id and depress it for the purpose of retracting the latch-bolt 3, but further movement will be prevented by the presence of the blocking tumbler I?" in the key slot. It will thus be seen that the function of the short key i8 is limited to retracting the latch-bolt only. If a long key 59 is used as shown in Fig. 4, it may be turned in a counter-clockwise direction to the position shown in Fig. 4 and beyond suificiently far to depress the tumbler 5 and permit the roll-back to project the dead-bolt t. When this rotation is completed, the roll-back will assume its normal position shown in Fig. 2 and the key may be withdrawn so that the door will be double locked with the latch-bolt 3 and deadbolt i. If the long key is again inserted, a clockwise rotation will cause the roll-back l2 to first pass the lever iii, then engage the tumbler 5 and withdraw the dead-bolt 4 so as to restore all parts to the position shown in Fig. 1. Now a partial turn to the right depresses lever ill and retracts the latch-bolt.

In Figs. 3 and 4 I have indicated the blocking tumbler H as somewhat nearer to the locking tumbler l6 than is the blocking tumbler II". This may be varied as occasion requires. In some instances, only one blocking tumbler may be em ployed to advantage. It will be observed that each blocking tumbler is of substantial length and thus has a relatively long and durable bearing that will offer sturdy checking resistance to the turning of the plug and which reduces any danger of jamming or functional failure of such parts.

While I have shown and described my invention in one preferred form, I appreciate that modifications may be made without departure from the spirit or scope of the invention as set forth in the following claims.

I claim:

1. In a cylinder look, a cylinder body, a 1'0- tatable plug therein having a longitudinal key slot in one side, locking tumbler sections in said plug and body, a plug blocking tumbler supported in a passage in said body for reciprocal movement only, the end of said blocking tumbler being beveled oif to be engaged by one edge of said key slot to be repressed thereby.

2. In a cylinder look, a cylinder body, a rotatable plug therein having a longitudinal key slot in one side, locking tumbler sections in said plug and body, a plug blocking tumbler supported in a passage in said body for reciprocal movement only, the end of said blocking tumbler being beveled off to be engaged by one edge of said key slot to be repressed thereby, said blocking tumbler being located in substantially the same cross-sectional plane as the rearmost set of locking tumblers.

3. In a cylinder lock, a cylinder body, a rotatable plug therein having a longitudinal key slot in one side, locking tumbler sections in said plug and body, a plug blocking tumbler supported in a passage in said body for reciprocal movement only, the end of said blocking tumbler being beveled off to be engaged by one edge of being beveled off to be engaged by one edge of said key slot to be repressed thereby, said blocking tumbler being positioned at a different angle from the axis of the plug to that of the locking tumbler section in said cylinder body, and a second blocking tumbler in said cylinder body in the side opposite said locking tumbler section.

5. In a cylinder look, a cylinder body, a rotatable plug therein having a longitudinal key slot in one side thereof, locking tumbler sections in said plug and body, a plug blocking tumbler mounted for reciprocation in a passage in said body, said blocking tumbler and passage being of angular cross-section to prevent the former from turning therein, the end of said blocking 1 tumbler being beveled to be engaged by one edge of said keyway to be repressed thereby.

6. In a cylinder look, a cylinder body, a plug rotatable therein having a longitudinal keyway in its side, key actuated locking means between said plug and body, a plug blocking tumbler mounted in a passage in said body for reciprocal movement only toward and from said plug, the end of said blocking tumbler being beveled on one side only and toward the plug locking means, for the purpose described.

7. In a cylinder look, a cylinder body, a rotatable key plug mounted therein and having a longitudinal key slot in its side, a passage in said body radial to the axis of the key plug, a nonrotatable blocking tumbler mounted in said opening for reciprocation only toward and from said plug, one side only of the end of said blocking tumbler being beveled, said bevel being located on the side toward the blocking tumbler, for the purpose described.

8. In a cylinder look, a cylinder body, a rotatable plug therein having a longitudinal key slot in one side, a passage in the cylinder body substantially radial to the axis of the plug, a

relatively long blocking tumbler mounted to reciprocate in said passage and supported by the walls thereof throughout a substantial portion of its length, the end of said blocking tumbler being beveled off at one side to form an inclined surface to be engaged by said plug at one side of said key slot for repression of said blocking tumbler when said plug is rotated in one direction.

9. In a cylinder look, a cylinder body, a plug rotatable therein and having a longitudinal keyway, a locking tumbler, a blocking device in said body for abruptly engaging when projected the wall at one side of said keyway to check rotation of the plug in one direction, the end of said blocking device being beveled off" at the opposite side for engagement by the opposite Wall of said keyway when said plug is rotated in the opposite direction to: free said blocking device from said plug.

10. In a cylinder look, a cylinder body, a plug rotatable therein and having a longitudinal keyway having an open back, a locking tiunbler mounted in said body, a blocking tumbler motmted to reciprocate only in said body at one side of said locking tumbler, the end of said blocking tumbler being beveled on the side toward the locking tumbler and having an abrupt shoulder at the opposite side, said shoulder being projectible into said keyway to block the limit of rotation of said plug in one direction and being displaceable from said keyway upon rotation of said plug in an opposite direction, said blocking tumbler being displaceable and rendered ineifective by a proper key filling that part of the back of the keyway adjacent the end of said blocking tumbler.

NORMAN B. HURD. 

